Health Economics Introduction Health Economics • …studies the supply and demand of health care resources and the impact of health care resources on a population. (Mosby Medical Encyclopedia 1992, p. 361) The 4 Basic Questions 1) 2) 3) 4) What combination of nonmedical and medical goods and services should be produced in the macro economy? What particular medical goods and services should be produced in the health economy? What specific health care resources should be used to produce the final medical goods and services? Who should receive the medical goods and services? The 4 Basic Questions 1) What combination of nonmedical and medical goods and services should be produced in the macro economy? a) Should the government spend more on missile defense or to reduce the number of uninsured children? b) Should the government spend more on education or prescription drugs for the elderly? The 4 Basic Questions (cont.) 2) What particular medical goods and services should be produced in the health economy? a) Should the government spend more on prescription drugs for the elderly or on home health care? b) Should the government spend more on research to cure cancer or on cancer screening programs? The 4 Basic Questions (cont.) 3) What specific health care resources should be used to produce the final medical goods and services? a) Should more ambulatory patients be cared for by nurse practitioners instead of physicians? b) When is medical vs. surgical management of a health condition appropriate? The 4 Basic Questions (cont.) 4) Who should receive the medical goods and services? a) Should all of the elderly receive prescription drug coverage from the gov’t, or only the low-income elderly? b) Should refugees receive free care in community clinics and hospitals? • Because resources are limited, health economists are concerned with determining what medical services to produce, how they should be produced, and who should receive them • As we will see in this course, the tools of economics can be applied to the health care sector to derive valuable insights about our health care system Health System Goals • Access to care – Who’s covered? – What’s covered? • Quality of care – Medical efficacy – Medical outcomes • Cost of care – Who pays? – How much? METHODOLOGY OF HEALTH ECONOMICS Normative versus Positive Analysis of the Health Sector • Normative analysis deals with the appropriateness or desirability of an economic outcome or policy. – What ought to be? – Which is better? • Positive analysis makes statements or predictions regarding economic behavior. – What is? – What happened? Normative Economics VS Positive Economics of the Health Sector • Normative Economics ranks resource allocations and the policies that generate them • Ranking a policy requires positive analysis Normative Analysis in the Health Sector 2 Literatures: • Normative analysis of the operation of health care, health insurance market, market failure, non-market institutional arrangements to improve efficiency and equity of financing, funding, organization and delivery of health care. • What is the most appropriate normative framework within which to carry out analysis in the health sector, focusing on welfarist and extrawelfarist frameworks? Efficiency and Normative Frameworks • Efficiency: the extent to which time or effort is well used for the intended task or purpose. (Doing things in the most economical way) – Technical Efficiency: Production is organized to minimize the inputs required to produce a given output – Production efficiency: Production is organized to minimize the cost of producing a given output – Allocative efficiency: (demand-side) resources are produced and allocated so as to produce the optimal level of each output Neo-Classical Welfare Economic Framework • Utility Maximization – Behavioral assumption – Individuals choose rationally • Individual Sovereignty – Individuals are the best judges of own welfare • Consequentialism – Any action, choice or policy judged in terms of consequent effects. Outcome matters, not process • Welfarism – Goodness is judged on utility levels attained Neo-Classical Welfare Economic Framework • Two theorems of Welfare Economics – The allocation of resources generated by a perfectly competitive market process is Pareto Optimal • Acheives all three levels of efficiency – Any Pareto Optimal allocation can be achieved through a perfectly competitive economy. Welfare Economic Framework • Individual Sovereignty • Welfarism – Willingness-to pay as a monetary metric for utility • Welfare economics takes market allocation as the reference standard • Separation of efficiency and equity – Exclusive focus on efficiency Critiques of Welfare Economics in the Health Sector • Assumption of Individual Sovereignty is violated in health sector • Willingness to pay loses it normative relevance – Value of a health care service to an individual is not accurately represented by WTP • When health care service is a life or death issue, its value or benefit not linked to ability to pay of an individual Extra-Welfarism • Utility is not the only relevant argument – Health, not utility is most important outcome for normative analysis – Health care should be allocated to maximize level of health of the nation instead of the utility consumers derive as they utilize the health services (Feldstein, 1963) • The concept of need (as opposed to demand) Positive Economics of the Health Sector • Health Econometrics – Econometrics literature in health economics – Translating Heath economics to a wider audience • Identification and Estimation – The evaluation problem – Are we able to identify causal effects from empirical data? The Evaluation Problem – Randomized experimental design • Individuals are randomly assigned to the treatment group and control group (RCTs) – Natural experiment • Look like a controlled experiment • Mechanism that assigns individuals to treatment and control groups is not random • Event happens naturally that affects some and not others • Naturally occurring event is assigned as if random (exogenous) The Evaluation Problem • Most econometric studies rely on observational data, gathered in a nonexperimental setting • Data are prone to problems of non-random selection and measurement error, which may bias estimates of causal effects Model Specification • Finding an appropriate stochastic model to fit available data • Many times classical regression analysis assumptions are not met with available healthcare data – Linearity, normal distribution of error term • Individual level survey data common in healthcare are nonlinear Examples of Nonlinear data • Binary responses in survey data (0,1) • Multinomial responses (0,1,2,3) • Limited dependent variables: – expenditure data (censored at 0) • Integer counts – Number of visits to the Dr. • Duration measures – Time elapsed between visits Nonlinear Models in Health Economics • Maximum likelihood (ML) estimation – Properties: consistent, asymptotic normality – ML models need to be fully and correctly specified – Used for qualitative or limited dependent variables • Pseudo or quasi maximum likelihood (PML) – Models do not have to be correctly specified – PML estimator of the conditional mean is consistent and asymptotically normal for binomial, normal, gamma and Poisson distributions – PML used in count data regressions in health economics Qualitative Dependent Variables • Binary Responses – Binary dependent variable • Participant or non-participant in health insurance; smoker vs non smoker, etc E(yi|xi) = P(yi =1|xi)= F(xi) • Could be estimated as a linear function – weighted least squares • Could be estimated as nonlinear function – Logit model (assumes standard logistic distribution) – Probit model (assumes standard normal distribution) Qualitative Dependent Variables • Multinomial and ordered responses – Ordered probits, grouped data regressions • e.g. Self assessed health: excellent, good, fair, poor • Average daily ciggarete consumption – Multinomial logit – Nested multinomial logit • Impact of user fees on the demand for medical care in Peru • Decision to seek care; condition on decision on which provider to use (public, hospital, private doc) – Multinomial probit model Limited Dependent Variables • Two part models, • Selectivity models – Semiparametric estimators, • Hurdle models – Box-Cox double hurdle model Estimation Strategies in Health Econometrics • Estimating treatment effects – Longitudinal (panel) data: repeated measurements for a person allows opportunity to control for unobservable individual effects which remain constant over time. – Instrumental Variables: Instruments are good predictors of the treatment, and not related to the outcome – Control function approaches to selection bias • Parametric and non-parametric methods Bootstrapping Methodology • Many estimators in HE rely on asymptotic theory approximations. • When asymptotic theory is unknown or finite sample properties of an estimator are unknown, use bootstrapping . • Bootstrapping aims to reduce bias and provide more reliable confidence intervals • Boostrap data: repeated re-sampling of estimation data using random sampling with replacement • The bootstrap sample is then used to approximate the sampling distribution of estimator being used. Unobservable heterogeneity and simultaneous models • Linear models – Instrumental variables – MIMIC models • Nonlinear models – Switching regressions – Simultaneous estimators Longitudinal and Hierarchical data • Multilevel models • Panel Data – Random versus fixed effects Nonparametric and semiparametric estimators • Estimators rely on assumptions about – functional form of the regression equation – Distribution of the error term • Rosenblatt-Parzen kernel density estimator – Uses weighted local averages to estimate probability density functions of unknown forms Count data regression • Count data – Dependent variable is a non-negative integervalued count, – Y=0,1,2,…. – Used when dependent variable is skewed to left – Contains large numbers of zeros – E.g. health care utilizations, # of prescriptions dispensed – # of drinks over 2 weeks Duration analysis • Survival and Duration data – ‘Time until failure’ – E.g. individual life span; mortality rates – Used in context of individual health production